JPS6122573Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present application relates to a dental handpiece that has a built-in air motor and is configured to drive a cutting tool and change the driving direction thereof.

Hitherto, this type of dental handpiece has been known, for example, in Japanese Utility Model Application Publication No. 57-23310, and its assembly is such that an air motor and an air circuit member are sequentially fitted into a cylindrical gripping portion from one side to the other. Therefore, the assembly and repair work of the air motor were troublesome, and there were defects such as insufficient airtightness of the air circuit. Therefore, the present application has solved such drawbacks, and the embodiments of the present application will be described in detail below with reference to the drawings. 1 is a cylindrical motor casing that constitutes a part of the gripping part of the dental handpiece; The casing 1 is composed of a front cylindrical portion 2 and a rear cylindrical portion 3 having an inner diameter slightly smaller than the front cylindrical portion 2 via a step p. Reference numeral 4 denotes a partition plate which fits tightly into the front cylinder part 2 and whose periphery is received by the step part p to partition the front cylinder part 2 and the rear cylinder part 3; 45° square 2
Ventilation holes 5, 5' are provided by cutouts at various positions, and a through hole 6 is provided in the center.
Reference numeral 7 denotes an air motor that is fitted and mounted inside the front cylinder part 2 of the motor casing 1, and the air motor 7 has an eccentric cylindrical hole 8 inside and is tightly fitted inside the front cylinder part 2. A cylindrical stator 9 is provided with a positioning sphere 10 on its outer periphery, and a slit 11 extending in the axial direction with a 90° angle in a certain angle view is provided on the circumferential surface of the shaft portion, and both ends thereof are a bearing member 1 to be described later.
2 and 12', a rotor shaft 13 is supported at a central axis position of the stator 9, that is, at a position eccentric to the cylindrical hole 8, and a plurality of blades 14 are fitted into each of the slits 11 so as to be freely retractable. The stator 9 has an L-shaped air supply recess 15 for introducing pressurized air and an L-shaped exhaust recess 16 for discharging the pressurized air on the outer peripheral surface of the stator 9. are formed in each of the recesses 15 and 16, and through holes 15' and 16' that communicate with the eccentric cylindrical hole 8, respectively, are bored therein. Reference numeral 17 denotes a bearing member 12 that is tightly fitted into the front cylinder portion 2 of the casing 1 so that its rear end surface closes the front end surface of the air motor 7, and supports the front output shaft 18 of the rotor shaft 13 on the front surface of the center portion.
The retaining plate 17 is constructed by screwing the outer circumferential surface of an annular tightening member 20 into a threaded portion 19 provided on the inner periphery of the front end of the front cylinder portion 2 of the motor casing 1. It is brought into close contact with the front end surface of the air motor 7, so that the rear end surface of the air motor 7 is brought into close contact with the front surface of the partition plate 4, and the periphery of the partition plate 4 is brought into close contact with the stepped portion p. Reference numeral 21 denotes a connecting tube that is fixed to the front end of the tightening member 20 with a screw 22. This connecting tube 21 is equipped with a cutting bar at its tip (not shown) and is connected to the front output shaft 18 of the rotor shaft 13 inside. A tip member a having a rotating shaft is removably connected via a locking/disengaging mechanism 23. Reference numeral 24 denotes a rotation control member consisting of a shaft member rotatably fitted tightly into the rear cylinder portion 3 of the motor casing 1, and the rotor shaft 13 is disposed at the center of the front surface of the rotation control member 24.
A bearing member 12' for bearing the rear end portion is provided, and a boss portion 25 is provided at the center of the rear surface. This rotation control member 24 has a rear end inside the boss portion 2.
an air supply passage 26 that opens at the rear end surface of 5 and whose front end opens in an arc shape around the front surface;
A pair of exhaust passages 27 and 28 are provided, each of which has its front end opened at a position spaced from the front end opening 26' of the air supply passage 26 by an equal angle, for example, a 90' angle, in the left-right direction. Reference numeral 29 denotes an operating ring rotatably fitted to the rear outer periphery of the motor casing 1 via an O-ring 30;
A connecting screw 31 extending in the radial direction is attached to 9, and this connecting screw 31 extends in the radial direction of the rotation control member 24 through a long hole 32 in the circumferential direction formed in the motor casing 1, and is screwed into the rotation control member 24. Therefore, by rotating the operating ring 29, the rotation control member 24 is rotated within the range of the elongated hole 32. Reference numeral 33 includes a fitting recess 34 located at the center on the front surface and tightly fitting the boss portion of the rotation control member 24 in a rotatable manner; The air supply passage 2 of the rotation control member 24 has an annular recess 35 that is always in communication with the rotation control member 24 and a rib 36 that protrudes along the outer periphery, and extends in the axial direction through the center thereof.
6, and an exhaust hole 38 that communicates with the annular recess 35 and has a rear end open on the outer peripheral surface.
The joint member is also provided with a joint cylindrical portion 39 for connecting a flexible hose (not shown) that protrudes rearward and supplies pressurized air and water, and is screwed onto the outer periphery of the rear end of the motor casing 1. and the rib 3
6, the front surface of the rotation control member 24 is attached to the rear surface of the partition plate 4, and the joint member 33 is attached to the rear surface of the rotation control member 24.
The front surfaces of the rotation control members 24 are pressed together to allow rotation of the rotation control member 24, respectively. An air supply pipe 41 is connected to the rear end of the air supply hole 37 and receives pressurized air from a flexible hose, and 42 is provided at the rear of the joint member 33 in parallel with the air supply pipe 41. A water supply pipe 43 receiving water supply from a flexible hose is a water conduit pipe protruding from the outer periphery of the joint member 33, the inner end of which communicates with the water supply pipe 42 within the joint member 33,
A water guide tube 44 is connected to the outer end for directing water to the cutting part of the tooth. Reference numeral 45 denotes a terminal ring attached to the outer periphery of the rear end of the joint member 33, and a passage 46 is provided between the inner periphery of the rear end and the joint cylindrical portion 39 for allowing outside air to pass through the exhaust hole 38.
is formed. 47 is a sphere for positioning the joint member 33 with respect to the motor casing 1, 48 is a noise filter, and 49 is a slit that engages with the positioning sphere 10 formed on the inner peripheral surface of the front end of the air motor 7. Thus, the stator 9 is positioned relative to the air motor 7 in the circumferential direction and the stator 9 is stopped from rotating.

Therefore, when assembling the dental handpiece, the air motor 7 is interposed between the partition plate 4 and the holding plate 17, and both ends of the rotor shaft 13 are supported by the bearing members 12, 12'. By fitting into the front cylindrical part 2 from the front of the motor casing 11 and screwing the tightening member 20 onto the threaded part 19 of the motor casing 1 and tightening it,
The peripheral part of the rear surface of the partition plate 4 is connected to the stepped part p, and the air motor 7
The rear surface of the partition plate 4 is pressed against the front surface of the partition plate 4, the rear surface of the holding plate 17 is pressed against the front surface of the air motor 7, and the connecting tube 21 is fixed to the front surface of the tightening member 20 with a threaded rod 22. Next, the rotation control member 24 is fitted into the rear cylinder portion 3 from the rear of the motor casing 1, and the front surface of the joint member 33 is brought into contact with the rear surface, and then the cap nut 40 is screwed into the rear end of the motor casing 1. Then, the front surface of the rotation control member 24 is placed on the rear surface of the partition plate 4, and the joint member 33 is placed on the rear surface of the rotation control member 24.
The main parts are assembled by pressing the front surfaces of the parts together. At this time, the air motor 7 and the joint member 33
The positioning spheres 10 and 47 determine the position in the circumferential direction and stop the rotation thereof.

When pressurized air is supplied in the state shown in FIG. The rotor shaft 13 is driven, and the pressurized air after being driven flows through the exhaust passage 27 and the annular recess 3.
5. The air is discharged to the outside air from the rear end of the terminal ring 45 through the exhaust hole 38. Also, by rotating the operating ring 29, the rotation control member is rotated approximately 90 degrees, and the fifth
When setting as shown by the imaginary line in Figure A, the air motor 7 is rotated in the opposite direction as in the conventional case.

As described above, according to the present application, the air motor and the air passage can be easily formed and disassembled, which is convenient for repair work. The air motor is fixed by pressure, and the rotation control member is rotatably pressed by tightening a cap nut on the rear side of the air motor, so the air circuit can be sufficiently airtight and drive efficiency can be improved. has advantages.

[Brief explanation of the drawing]

The drawings show an embodiment of the present application, and Figure 1 shows the main parts at 90.
Figure 2 is a vertical cross-sectional view showing the air motor, Figure 3 A and B are plan views and end views of the stator, and Figure 4 A and B are cross-sectional views showing the partition plate. FIGS. 5A, 5B, and 5C are an end view, a vertical sectional view, and a horizontal sectional view of the rotation control member. In the figure, 1 is the motor casing, 2 is the front cylinder part, 3 is the rear cylinder part, 4 is the partition plate, 5, 5' are the ventilation holes, 7 is the air motor, 15 is the air supply recess, 16 is the exhaust recess, 17 18 is a holding plate, 18 is an output shaft, 20 is a tightening member, 24 is a rotation control member, 26 is an air supply path, 27,
28 is an exhaust path, 37 is an air supply hole, 38 is an exhaust hole, 4
0 is a bag nut, and p is a stepped portion.

Claims (1)

[Scope of utility model registration request] A front cylinder part with a slightly larger inner diameter and a rear cylinder part with a slightly smaller inner diameter are formed separately through a stepped part in a cylindrical motor casing constituting a part of the gripping part, and
A partition plate having a pair of ventilation holes around the periphery, an air motor having an air supply recess and an exhaust recess facing the pair of ventilation holes, respectively, and a retaining plate are successively tightly fitted into the front cylinder part. These are press-fixed in the direction of the stepped portion by a tightening member screwed onto the front end of the motor casing, and the output shaft of the air motor is connected to the rotating shaft of the cutting bar. A rotation control member having an air supply passage and an exhaust passage therein which are in communication with a pair of ventilation holes provided in the rear side thereof is tightly fitted therein, and an air supply hole and an exhaust air which are in communication with the air supply passage and the exhaust passage, respectively, are fitted on the rear surface thereof. A dental handpiece equipped with an air motor in which a joint cylindrical part having a hole is joined together and pressed in the direction of the partition plate by a cap nut screwed onto the rear part of the motor casing.